Signaling arrangement for telephone systems



Feb. 9, 1932. H. M. BASCOM ET AL 1,844,027

' SIGNALING ARRANGEMENT FOR TELEPHONE SYSTEMS Filed June 18, 1931 Ii] 3" 1111 4 2 L INVENTORS I flmmwmfliffflhm ATTORNEY Patented Feb. 9, 1932 PATENT OFFI I IIENRY M. BASCOM AND STANLEY NELSON, OF BROOKLYN, NEW YORK, ASSIGNORS TO AMERICAN TELEPHONE All TELEGRAPH COIIIPANY, A CORPORATION OF NEW ill YORK

Application filed June 18,

This invention relates to telephone systems and more particularly. to improvements in signaling arrangements associated with the lmes oi such systems.

' battery central offices of the type inwhich the line lamp is lighted 111 series with the line rather than over a local circuit from the contacts of the line relay. When the line lamp .is associated in series with the subscribers line in installations of this type, instances might arise, when the subscribers line was a long one, wherein the resistance of the long line would be so great that it might be impossible to obtain suificient'brilliancy of the line lamp a positive signal of an incoming'call. By associating the auxiliary signaling arrange-v ments of the invention with the line lamp in installations of this type a proper brilliance of the lamp, or in other words an adequate signal, may be assured.

The arrangements of the invention utilize a diiierentially wound relay connected in parallel with the line lamp for completing an auxiliary local operating circuit therefor at the central oiiice. One of the advantages of utilizing a relay of this type'connected in the manner described, rather than a single wound relay connected across the line, for completing a local operating circuit for the line lamp is the ease with which it may be associated with the desired line without altering the wiring of the switchboard. Other objects and features of the invention will appear more fully from the detailed description of its operation hereinafter given.

The invention may be more fully under= stood from the following description together with the accompanying drawing in the figure 1 of which is a circuit diagram illustrating the invention.

In the drawing is shown a subscribers telephone line L, terminating at a switchboard at a central o'liice, in the ack J. A portion of an operators cord 6, terminating in the. plug P, adapted to connect with the jackJ, is shown. The telephone line L extends to a subscribers station including ringing app ara;

to give the operator.-

proper signal to the operator at the central SIGNALING ARRANGEMENT FOR TELEPHONE SYSTEMS 1931. Serial No. 545,300.

ring side of the line L will be grounded, as

shown at 7 The tip side of the line will be extended by conductor 8 through the linesignal lamp 9 to battery 10 and ground. When the subscriber removes his receiver fromthe switchhook 5, a circuit will be closed from ground 7 over the ring side of the line, through the subscribers set, over the tip side of the line, over conductor 8, filament of lamp 9 to battery 10 and ground. When the subscriber removes his receiver from the switchhook 5, a circuit will be closed from ground 7 over the ringside of the line,through. the subscribers set, over the tip side of the line, over conductor 8, filament of lamp 9 to battery 10 and ground. If the line L should be a long one, its resistance might be so great that the lamp 9 would not light with the usual brilliance and a proper signal might not be givento the operator at the central oflice. Accordingly, the arrangements of the invention provide an auxiliary local circuit for the line lamp 9 at the central oflice. This circuit will include one of the differentially arranged windings of a relay 12. When the previously traced circuit for the line'lamp is closed by removal, of the receiver fromthe switchhook at the subscribers station, ground will .be applied to conductor 11 and through the ground over itsarmature and contact to'the left hand winding of the relay, However, the windings of the relay are so designed that the efiectof thecurrent through the righthand winding will overcome the effect of current v through the left hand winding and the relay will remain held operated. The following local circuit for the line lamp 9 will then be completed; from ground, armature and con tact of relay 12, left hand winding of relay- 10 and ground. As this circuit is of relatively small resistance, the line lamp willhe operated with its customary brilliance to give the 12, conductor 11, filament of-lamp, 9 to battery ;so that the effect of the current in the left hand winding will be equal and opposite to the effect of the current in the right hand winding and the relay will be released. This will restore the circuit to its normal condition.

While the invention has been disclose-d as embodied in certain specific arrangements which are deemed desirable, it is understood that it is capable of embodiment in 'many and other widely varied forms without departing from the spirit of the invention, as defined by the appended claims.

lVhat is claimed is:

1. A telephone signaling system comprising a subscribers telephone line terminating at a central office, a line signal lamp connected in series with said line at said central oiiice, relay means connected in parallel with said lamp, and means controlled by said relay for completing a local auxiliary operating circuit for said lamp at said central office.

2. A telephone signaling system comprising a subscribers telephone line terminating ata central office, a line signal lamp connected in series wth said line at said central office, a difierentially wound relay having an operating winding connected to said subscribers line in parallel with said lamp, and means for completing a local auxiliary operating circuit for said lamp through the other winding of said relay.

3. A telephone signaling system comprising a subscribers telephone line terminating at a central oflice, a line signal lamp connectedinseries Withsaidline to battery at said central office, an auxiliary circuit connected from battery to said subscribers line in parallel with said lamp at the central oflice, and a differentially wound relay having an operating winding included in said auxiliary circuit and means controlled over its armature and contact for connecting its other winding to ground.

4. A telephone signaling system comprising a subscribers telephone line terminating at a central office, a line signal lamp connected in series with said line to battery at said entral ofiice an auxiliary circuit connected from battery to said subscribers line in parallel with said lamp at the central oflice, and a differentially wound relay having an operating winding included in said auxiliary circuit and means controlled over its armature and contact for connecting its other winding to ground, said operating winding being designed to normally have greater effectiveness than the other winding of said relay.

5. A telephone signaling system comprising a subscribers telephone line terminating at a central office, a line signal lamp connected in series with said line to battery at said central ofiice, an auxiliary circuit connected from battery to said s'ubscribers line in parallel with said lamp at the central ofiice, and a differentially wound relay having an operating winding included in said auxiliary circuit and means controlled over its armature and contact for connecting its other winding to ground, said relay windings being so designed with respect to said circuits that the effectiveness of the operating winding will be greater than the effectiveness of the other winding of said relay when said telephone line is closed and the effectiveness of said windings will be equal when said telephone line is opened.

In testimony whereof, we have signed our names to this specification this 17th day of June, 1931.

- HENRY M. BASCOM.

STANLEY F. NELSON. 

